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UNITED STATES PATENT OFFICE.

JN0. TAGGART, or RoXBUaY, MASSACHUSETTS, AssIGNoR To HIMSELF AND THnoDoRE D.

PARKER.

ARTIFICIAL LEG'.

Specification of Letters Patent No. 13,611, dated September 25, 1855.

To all wiz-0m t may concern Be it known that I, JOHN TAGGART, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented an Improved Articial Leg; and I do hereby declare that the same is fully described and represented in the following specification and the accompanying drawings, letters, figures, and references thereof.

In the said drawings, Figure 1, denotes a side elevation, and Fig. 2, a vertical, central and longitudinal section of one of the said artificial legs. Fig. 3 is a view of the bottom of the foot thereof.

The lower part, A, of the leg, or that part which is below the knee, as well as that portion B, which is above the knee, I construct mostly of thin sheet metal or other suitable material, making the part, B, a case for the reception of the thigh of a person when the leg is in use. The two parts A, and, B, are to be united together by a hinged joint as Seen at C.

Instead of making a joint at the ankle in the usual way, I construct the foot with no such joint at the ankle, but arrange a joint in the instep of the foot or about midway between the ankle at, a, and the ball of the foot as seen at, b, such joint being exhibited at, D, the foot being made with a toe joint also as represented at, E.

IVithin a recess, F, formed along in the underside of the foot there is arranged a long spring G, which extends from near the front end of the toe block, H, back into the heel, the front half of the spring being made to rest upon two bearers or transverse rods f, f. The said spring also abuts on its upper side against a bearing in the front part of the bottom of the instep part of the foot as seen at, h. Upward from and through the rear end of the spring G, a rod, I, ex tends, such rod being provided with a screw and nut on its lower end as seen at, K. The rod, I, passes up through and rests upon the upper end of a helical spring L, which is placed within a case or tube M, and rests on the bottom thereof, the said tube or spring case being arranged within the hollow of the part A, of the leg and connected to the rear portion of the lower part of the thigh case, B, by one or more tendons or straps, N.

The knee joint is provided with a spring Stop as seen at, O, which when the two portions, A and B, of the leg are brought into a straight line with one another brings up against a shoulder P. The object of such spring stop is not only to arrest the for* 1 ward movement of the part B, upon the part, A, but to maintain them in a straight line with each other while the leg is being thrown forward during the act of walking, or while the wearer of the leg is in a standing position. A slight back throw of the leg will suffice to unlatch the spring catch when necessary, as it should be made so as to enable such to be effected.

By lattaching the instep part of the foot firmly to the leg wit-hout any joint between them and providing the foot with a joint at the instep or between the ankle and the ball as hereinbefore specified, agreat advantage results in the use of the leg, as the instep portion of the foot, by constituting a firm rest or support for the foot, while the leg is being straightened, not only facilitates the straightening of the leg, but causes the leg during its further movement to rock or turn upon the lower part of the front end of the said instep part so as to lift the heel off the ground. As soon as the weight of the body is thrown upon the other leg, or taken from off the artificial leg, the action of the springs G and L, is such as to bend the knee, and throw the heel still higher above the ground, and so far clear of it as to admit of the leg being readily moved forward by the wearer, for the purpose of taking another step.

It should be remarked, that each joint of the foot should be so constructed as to allow that part of the foot which is in front of it to be turned upward in respect to the part which is in rear of it.

lVhile a person is sitting down, and the leg is bent at the knee so that the two parts, A, and, B, shall stand at nearly right angles to each other the tendon N, will be slackened so as to release from the spring, G, the tension or strain of the sp-ring L, the front parts of the foot thereby being relieved in a great measure from the strain of the spring L. Under such circumstances, such parts of the foot can be easily moved or bent upward by downward pressure exerted on the leg. Thus while a person is in a sitting posture, he can impart to the foot, upward bends,

which will render it more natural in appearance that when unbent.

By combining with the toe springs, G, and, L, the screw and nut as seen at, K, We are enabled not only to adjust the tension of the springs to the convenience and Cornort of any individual who may wear the leg, but can regulate such, should their elasticity ever become lessened by use, of the parts.

An artificial leg constructed in my iinproved Inanner can be Worn and used with great ease, its motions approximating very closely to those of a natural leg.

I Claim- 1. Making the leg and foot without any ankle joint in combination with Ina-king the foot with an inste joint or equivalent substantially as speci ed.

2. I also claim combining together and with the foot, the part, A, and the thigh Case B, the two springs, Gr, and, L, so as to operate therewith substantially and for the purposes as specified.

In testimony whereof I have hereunto set my signature this thirteenth day of J une A. D. 1853.

JOHN TAGGART.

Witnesses:

R. H. EDDY, F. P. HALE, J r. 

